Revertive-call-indicating means for telephone-exchange systems.



A. M. BULLARD, DBOD. '1a. R. BULLABD. ADMINISTRATRIX.

REVERTIVB CALL INDIGATING MEANS POR TELEPHONE EXCHANGE SYSTEMS.

APPLIUATION FILED JUNE 4, 1909.

UNITED sTATEs PATENT OFFICE.

ALBERT M. VIBUIICLAIRI), DECEASED, BY MARION R. BULLARD, ADMINISTRATRIX', OF NEW YORK, N. Y., ASIGNOR TO WESTERN ELECTRIC COMPANY, F NEW YORK,

, N. Y., A CORPORATION 0F ILLINOIS.

Specication of Letters Patent.

Patented May 14, 1912.

Application led June 4, 1909. Serial No. 500,148.

I To all whom 'it may concern:

Be lit known that I, MARION R. BULLARD, administratrix, a citizen of theI United States, residing at New York, in the county and State of New York, am in possession of an invention in a certain new and useful Improvement in Revertive-Call-lndicating Means for Telephone- Exchange Systems, in-

vented by ALBERT M. BULLARD, deceased, ot, which the following is a full, clear, concise,

' `and exact description.

This invention relates to improved revertive call indicating means for telephone exchange systems having party lines and is particularly directed toward improvements on what is shown and described 1n the application of Albert M. Bullard, Serial No.

355,897, filed February 5, 1907. In such a system it frequently happens that a subscriber at 'one of the substations of a party line desires to communicate with a sub- ,scriber at another station of the same line.

- 'required to know from the mere number of the called station whether it is on the same party line as the calling station.

It is the purpose, therefore, 4ot this invention to provide improved means for giving a special signal in all cases of such revertive calls, that. is, where the terminal ot the called line which is tested is merely Ia multiple terminal ot the calling line. A

signal device is associated with the miginatl lng or answering end of the connecting eircuit which is united with any calling linein response to a call, and one terminal of said signal 'device is arranged to be connected thereby to a test conductor zwhich extends to contacts at all the multiple terminalsot such line. Testing apparatus associated with the other end of the connecting circuit i is adapted to connect the other terminal of I said signal device to the test conductor'of the called line, so that where the terminal tested is a multiple terminal of the calling ling, the circuit ofsaid signaling device will be completed and the signal given to indi cate that the call is revertive.

Preferably the special signal device is `brought into connection with the test conductor of the calling line only momentarily at the time of testing the called line; and at this time the usual test guard may be removed and the special revertive test circuit substituted therefor, tho test guard otherwise being maintained at all multiple terminals of the line during theentire period of connection therewith.

This invention willy be of especial utility in connection with semi-automatic systems of the type lin which calls are answered by an operator andconnection completed to the called line by means of automatic switching mechanism controlled by the operator.

The invent-ion is. illustrated in the accompanying drawing in its application to such a system. Only the circuits and ap-A paratus which are directly concerned with the invention are illustrated, however.

Two lines are indicated, each having answering and connecting terminals, the former being shown as springjacks and the latter as terminals located upon an automatic selector switch. One ot these lines- QQ-is supposed to be a party line having y several stations connected therewith, while the other linc-53-is of a diferent character, thatis, it may be, for example, a trunk line leading to a private branch exchange. In an automatic or semi-automatic system in which such private exchange trunk lines are provided in addition to party lines and ordinary subscribers lines', the testing apparatus must discriminate between ysuch trunk lines and other lines, to govern the appropriate operations of the automatic switching device which completes the connection. It is convenient to distinguish private 'exchange trunk lines from ordinary lines or party lines by electrical potentials of different polarities applied to the test conductors, respectively, of such different classes of lines.

One of the features of the present invention is the rovision of revertive testing apparatus whlch will be ada ted to syst-ems in which different classes of ines' exist, one of .suchclasses' comprising lines ,in .connection -105 with which wrevo'rt-iv test would not bex necessary or desirable. AMeans are therefore preferably provided for bringing the revertive signal device into service only when connection is made with a line of the proper class, such means consisting, for example, of a polarized relay brought into connection with the test conductor of a calling line and responsive to potential of the proper polarity received therefrom.

\In the drawing, 1, 2 and 3 represent respectively the tip, ring and sleeve of an op erators answering plug, while 4, 5 and 6 show the corresponding `answering jack terminals `of a subscriber-S line. Associated with the test conductor 7 of'this line, which will.be assumed to be a party line of usual 'construction and arrangement, is a cut-pff relay 8 Iwhich is connected to the negatfve pole of the grounded battery 9. The character of this. relay 8 and its association with the subscribers line is well-known and will not be further described.

10, 11 and 12representrespectively the charged with a positive Orr-negative potenlmult-iple contacts 16, 17 and 18 connec d respectively by thev conductors 19, 20 an 21 tial, according to the character of the line with which they are associated. Both of th llnes referred to, however, are provided wi of the'tip, ring and sleeve ofthe va ous answering jacks of such lines. These muly. t-iple contactsare shown diagramma ically yator is'at-tracted in t-he usua way.

on the right hand side of the drawin as are also shown similar contacts of ot r lines terminating'in the exchange. W'hn a subscriber upon the line 22, which as above noted is assumed tov be aparty telephone line, desires connection with anther party f the oper- The operator thereupon inserts the plug 23 in the jack 24 in order to receive te call. Immediately upon the insertion o r this plug a test guard is\placed upon test conductor 21 of the calling line by means f a low resistance circuit to ground extendi g from the-sleeve contact 6 through the sle ve 3 of the answering plug, conductor 25,/contacts 26, conductar27, low resistance lwinding 28 of therelay 29 to ground. This'provides a path for current from the battery 9 which operates the relay 8 in the usual manner, and lowers the normalpotential upor'the sleeve or test on the same line the attention contact 6 of the answering jack, and also ance winding 28, through the conductor 30 and the high resistance Awi ding 31 of the relay 29, which circuit, lowever, since it forms no Apart of this inv t-ion need not be further described.

The operator having le( rned from the calling subscriber the nul ber of Athe desired party causes the auton aticswitcbing device 32 at which the multiy le contacts 16, 17 vand 18 appear to bring ts Contact brushes 33, 34, 35 by any suit ble means, not shown, into Contact with ie multiple terminals 16, 17 and 13 of the ine on which the desired party is locate hen this automatic switching devic has made its final selective movement an the Contact brushes are in Contact with he multiple termina-ls ofthe desired 'lin suitable m ns to momentarily open the contacts 26 nd close the contacts 37. switch 3 may be arranged to be manually operate by the operator at the time desired, but isf/preferably arrangedto be automatically perated to close the contacts 37 and ope the contacts 26 at the proper time by l so e portion of the automatic apparatus of the system with which it is associated. e movement of this switch 36 will, as will e' seen, remove the test guard from the test e switch 36 is operated by any y This,

conductor'21 of the called line by the open-4 ing of the contacts 26, so that the connector 32 in testing the line will find itin idle condition, the winding 31 of the relay 29 being of suflicientlyhigh resistance not to reduce, appreciably, the potential l`of the sleeve contact 6 from its normal or idle potential due to the connection of the battery 9. By the same movement of the switch 36 there is connected withthe test conductor 21 through the contacts 37, conductor 25, sleeve 3, and the sleeve contact 6 of theanswering jack,

a high resistance circuit including conductor 38, conductor 39, polarized relay 40 and ground. This polarized relay 40 is so adjusted that it will only respond when the sleeve 3 is in contact with a sleeve contact which is negatively charged.

Since the sleeve contact 6 is, however, negatively 'Y charged from the battery 9,- the Vpolarized relay 40 will be operated andl close the contacts 41 controlled by the armature thereof,- whereby the battery 42 will be connected to the test conductor 2l through the conductor 43, contacts 41, conductor 44,.marginal relay 45, contacts 46, conductor 47, conductor 38, contacts 37 of the switch 36,- c

and sleeve 3. This battery 42 is loI ductor 25 he same polarity as the battery 9,'but will be inguif cient to energize the marginal relay 45 Vof the calling line, which condition will exist at this time 'if the call is a revertive one, a low resistance circuit will be established from the battery 42, including the marginal relay 45, the test conductor 21, the multiple test terminal 18, the test brush 35, conductor 48 and test relay 49 of the automatic switching device 32 to ground and back'to battery. The closure of this circuit will allow sufiicient current to pass from the bat. tery 42 to energize the marginal relay 45,g which will thereupon attract its armature 50 -and close a circuit fromI the battery 51 through the revertive signal 52 and ground back to battery to cause a display of this signal. The marginal relay having been once energized will be maintained energized by current from the battery 42 through the path including the high resistance polarized relay 40, so that the signal 52 will be maintained displayed until such time as the contacts 46 may be opened, which 4will occur at some suitable time, either under the control of the operator or automatically in some further stage in the operation of the system.

It has been up to this timeassumed that the call coming in over the telephone line 22 has been a revertive one, and, as described, the signal 52 is therefore displayed. If, however, the lcall has .not been a revertive call the final selective movement of the automatic switching device 32 will have placed the contact brushes 33, 34, 35 in contact with y the multiple terminals 16, 17, 18 of some line other than the calling' line.

No l'ow resistance circuit over the test conductor will -be completed atthis time for the marginal relay 45 and itwill remain inert, since,'as

`has been heretofore noted, insuicient cur! rent passes through the polarized relay 40 v 'and the high resistance winding 31 of the relay 29 to energize this marginal relay 45.

'The signal 52, therefore, will not be displayed.

Assuming now that 'a call is received over theline 53, which is of a different character 4 as before inserts the plug ,23 in the jack 54 in or er to receive the call. When, however,

'after .the final, selective movement of the Iautbmaticswitching device 32 has taken place' the switch 36 is momentarily operated, the closure of. the contacts '37 closesa path from the.; positive vbattery 15, through 'the desired.

semi-automatic or manual system.

relay 14, conductor 13, sleeve contact 12, sleeve 3, conductor 25, contacts 37 of switch 36, conductor 38, conductor 39, polarized relay 40 and ground back to battery. The current of the battery 15, however, is of the .wrong polarity and will not operate the polarlzed relay 40, and since contacts 41Yare not closed, the marginal relay 45 and the battery 42 will not be placed in operative relation to the test conductor 21 of the line 53 andthe revertive signal can not be displayed. y

'lhe connecting circuit, which 'is only dia- 4grammatically shown, since it inl 4itself forms no part of this invention, comprises 30 as is usual the ytip and ring conductors 55 and 56,.respectively, induction coil windings 57, 58, 59 and 60, and the grounded battery 63 connected across the tip `and ring conductors between respective windings of the induction coils. The usual supervisory re lays 61, 62 are also provided in the ring strand 56. The automatic switching device 32 audits associated test circuit 48y and test relay 49 are shown only so far as they are necessary -for full and definite understand-'- ing of this invention, and it will be, of course, understood that they may be of any ordinary'or usual construction that may be i It should be understood that in all cases where the originating end of the connecting circuit is referred to, either in the specification or claims, that end of the connecting circuit is meant which corresponds to the answering end of an operators cord circuit. in a manual system whether such connecting circuit be means for intercom' necting subscribers lines in an automatic,y

,Having fully described my invention, what I claim and desire to secure by Letters Patent of the United States is 1. In a telephone exchange system, the combination with` a party telephone line having multiple terminals, of a connecting circuit adapted to be united therewith, a' signal device associated withthe originating end of said connecting circuit, a circuit for said device independent of the talking circuit, and means including multiple ter: minals of said party line at each end of said connecting circuit for closing the circuit of said signal device, whereby said signal device will bc operated in the test-of a multiple terminal of the same line to which said connecting circuit is united at the originating end.

y2. In a telephone exchange system, the combination with a party telephone line having multiple terminals and Ia test conductor extending to contacts at all of said multiple terminals, of a connecting 'circuit adapted to be united with said lincat one 'of said,multiple terminals, :t signal device '130 yadapted to be temporarily associated with said line by said connectingl circuit, and

means for closing a circuit for said signal device through said test conductor and' corresponding multiple Icontacts of said connecting circuit at each end thereof, whereby said signal device will be operated whensaid connecting circuit is connected at both ends to the same line. 7

3. Ina telephone exchange system, the combination with a party telephone line having multipleterminals, of a connecting circuit adapted to be united with said terminals, a signal device associated with the originating'end of said connecting circuit, a circuit for said' signal device independent 'of thet-alking circuit and iiicludingnultiplet-erminals of said party line at each end of said connect-ing circuit, and a switch in said circuit momentarily operated to clo'se the circuit of said signal device, whereby said signal device will he operated by the closure of said switch when said connecting lcircuit is connected atbotli ends to the same lll@ 4. In a telephone exchange system, the combination with a party telephone line having multiple terminals, of a test conductor extending to contacts at all of said =multip1e terminals,^a connecting circuit adapted to be united with said multiple terminals, asignal device associated with the originating end of said connecting circuit, a circuit for-said signal device-independent of the `talkingcircuit and including said test conductor andcontacts at each end of saidconnecting circuit, and a switch in fsaid circuit, momentarily operated. to close the circuit of said signal device, whereby said signal device will be operatedliby the closure of said switch when said connecting circuitis connected at b otli ends to the same line.

5. ]n4 a telephhne exchange system, the combination with a party telephone line having multiple terminals, of a connecting circuitjadapted to be united therewith terminating in an automatic switching device,

one of saidmultiple terminals being located 1'n said switching device, test means associated with said switching device, a A#signal device, a circuit for said signal device including said test means and contacts ofsaid multiple terminals at both ends. of said connecting circuit, and a switch for closing the circuit of said signal device, whereby said signal device will beoperated by the clo sure of said switch in the test of a multiplev terminal'of the same line to which-said connecting circuit is united at its originating end. f

6. In al telephone exchangefsystem, the

combination with a party telephone line havin multiple terminals, ofa connecting circuit adapt-ed to be united therewith terminating in an automatic switching device, one

of said multiple terminals being located in said switching device, test means associated with said switching device, a signal device, a`

circuit for said signal device independent of the talking circuit including said test means and contacts of said multiple terminals at vboth ends of saidconnecting circuit, andfa switch for closing the circuitof said signal device, whereby said signal device will be operated upon the vclosure of said switch,

when said connecting circuit is in Contact at y both ends same line.

7. In a telephone exchange system, the com- `withfmultiple terminals of the bination with a party telephone line havingA y multiple terminals, of a test conductor ex-v f tending to contact at all of said multiple;

terminals, of a connecting circuit adapted to be united with said multiple terminals terminating in an automatic switching de-' vice, one of said multiple terminals being located in said -switching device, test means associated with said switching device, a

signal device, a circuit for said signal de vice including said test conductor and said test means, and a switch for closing the circuit of said signall device, whereby said signal device will be operated upon the closureof said switch, when said connecting circuit minals of the same line. 4

.8. In a telephone exchange system, the

is iii contact at each end with multiple-terlcombination with a party telephone lline having multiple terminals, of a test fconductor eXtendingto contacts at all of said multiple terminals, some of said terminals being located upon'aut-omatic switching devices,'an answering switch adapted to make contact with the linevwhn calling, a signal device adapted to bel connectedlto said test .conductor -by said answering switch, an auto- 'matic switching device to whichconnection 9. In a telephone exchange system,4 the combination with a party telephone line having multiple terminals, of a connecting circuit. adapted to be united therewith,

means associated with said connecting cir' cuit for placing a test guard upon said party line, a signal device, a circuit for said-signal device independent of the talking circuit and including said multiple terminals at both ends of said connecting circuit, and means for removing said test guard and closing l'the circuit of said signal device.

l0. In a telephone exchange system, the combination with a party telephone line having multiple terminals and a test conductor extending to a contact at all o t' said multiple terminals, of a connecting circuit adapted to imite with said multiple terminals, means associated lwith said connecting circuit for placing a test guard upon said party line, a signal device, a circnitfl'or said signal device including the test conductor ot said party line and multiple contacts thereof, and means for removing said test guard and closing the circuit of said signal device.

11. In a telephone exchange system, the combination with telephone lines of different character terminating in an exchange, a connecting circuit arranged to be connected With a callingv line, a signal device, a circuit for said ysignal device including contacts associated with said calling line at both ends of said connecting circuit, and means for closingy said circuit operated if the calling line is of a particular character.

12. In a telephone exchange system, the combination Witli'telephone lines of ditl'ercnt character terminating in an exchange, a connecting circuit arranged to be connected with a calling line, a signal device, a circuit for said signal device independent of the talking circuit and including contacts associated with said calling line at both ends of said connecting circuit, and means for closing said circuit operated if the calling line is of ay particular character.

13. In a telephone exchange system, the combination with telephone lines of different character terminating in an exchange, a connecting circuit arranged to he connected with a vcalling line, a signal device, a' circuit for said signal device including the test conductor of a calling line and multiple contacts thereof, and means for closing said circuit operated if the calling line is of a I particular character.

llt. In a telephone exchange system, f urv combination with telephone lines of diilerent character terminating in an exchange and having multiple terminals, a connecting ciicuit adapted to be united `with said multiple terminals, a circuit associated with said connecting circuit arranged to he connected to the test conductor ot' a callingrv line, electromagnetic means in said circuit arranged to be operated when the line with which said circuit is connected'is ot' a particular char-` acter, a signal device under the control. of said electroniagnetic means, a circuit for said signal device inclinling multiple terminals et the calling line at both ends of said connecting circuit, and means :for closing the circuit of said signal device.

l5. In a telephone exchange system, the combination with a party telephone line having multiple terminals, a test conductor extending to contacts at each ot' said multi* ple terminals, a source of current connected `to said test conductor, a connecting circuit adapted to be united with said line at one oi said multiple terminals, a second source of ciu-rent of the same polarity as said first mentioned source of current, means Jtor connecting said second source of current to said test conductor at the originating end of said connecting circuit, a signal device, test means associated with said connecting circuit adapted to test the desired line, and a circuit for said signal device including saidl second source of current, said test conductor and said test means. U

In Witness whereof, I hereunto subscribe my name this second day of June, A. D.

4 MARION R. BULLARD, Administrativa of the estate of Albert Ml Bullard, deceased'. Witnesses:

W. C. LANGnoN, InviNc MACDONALD. 

